饲喂不同浓度黄曲霉毒素B_1饲料对异育银鲫成鱼的生长和毒素积累的影响

以含不同浓度黄曲霉毒素B1(AFB1)的配合饲料饲喂异育银鲫(Carassius auratus gibelio)成鱼56d,研究异育银鲫成鱼[(122.3±0.7)g]生长、生理反应、肝脏组织学变化、卵巢发育以及鱼体各组织中的AFB1的毒素积累状况。实验分为5个实验组,不同实验组饲料中AFB1含量分别为0、5、20、50、500μg/kg饲料(实测值分别为2.59、4.12、12.39、46.23、454.07μg/kg饲料),每个处理3个平行。在整个实验过程中各实验组均未表现出外部形态和行为异常,各组存活率均达到100%。各实验组异育银鲫成鱼终末体重、摄食率(FR)、特定生长率(SGR)和饲料效率(FE)均无显著差异。饲料AFB1水平对异育银鲫血清总胆固醇(TC)含量、血清谷丙转氨酶(GPT)、谷草转氨酶(GOT)和碱性磷酸酶(AKP)活性均无显著影响。各毒素组血清超氧化物岐化酶(SOD)活性与对照无显著差异。各毒素组肝脏和卵巢均未见明显的组织学病理变化。肌肉和性腺中的AFB1积累量低于FDA食品安全限定标准(5μg/kg)。肝胰脏中的AFB1积累和饲料中的AFB1水平呈对数关系。饲喂AFB1≥50μg/kg饲料使异育银鲫成鱼肝脏AFB1积累超过安全限量标准。结果表明,异育银鲫成鱼至少可耐受AFB1含量达500μg/kg饲料(实测值:454.07μg/kg饲料)56d

人民币实际有效汇率失调对房地产价格的影响

房地产行业是我国国民经济的重要支柱产业。2005年我国汇率制度改革后,人民币单向升值的预期吸引了大量境外资金流入,推动房价快速上涨。随着我国汇率制度改革及资本项目开放的推进,汇率...中央高校基本科研业务费专项资金资助项目“人民币离岸金融市场发展研究”(20720161053

知母皂苷元对体外培养皮层神经元树突发育的影响及信号转导机制

目的探讨知母皂苷元(Sarsasapogenin,SAR)对大脑皮层神经元树突发育的促进作用及其信号转导机制。方法选用出生0～24 h的Sprague-Dawley(SD)大鼠乳鼠,取皮层神经元进行体外细胞培养,4 d后用于实验。倒置相差显微镜测量培养神经元树突分支总长度(TDBL)、一级树突数目(PDN)、最大分支级数(MBO)和神经元胞体面积。West-ern blot法观察神经元p-PDK1、p-Akt473及p-mTOR蛋白表达。结果形态学观察结果显示SAR(10、30、100μmol.L-1)可明显促进树突发育,表现为树突分支总长度增加、一级树突数目增多、最大分支级数增大及胞体面积增大,并呈明显浓度依赖。SAR 30+LY组、SAR 30+TCBN组、SAR 30+Rapa组的神经元树突总长度、一级树突数目、最大分支级数及胞体面积较SAR30μmol.L-1组明显降低。Westernblot结果显示SAR 30也可明显增加p-PDK1、p-Akt473及p-mTOR蛋白表达水平。SAR 30+LY组明显降低神经元p-PDK1、p-Akt473及p-mTOR的蛋白表达水平。SAR 30+TCBN组明显降低神经元p-Akt473及p-mTOR的蛋白表达水平。SAR 30+Rapa组明显降低神经元p-mTOR的蛋白表达水平。结论 SAR对体外培养皮层神经元树突的发育有促进作用,这种作用可能与PI3K/Akt/mTOR信号转导通路有关

Topological Properties of the Evolution of Two-dimensional Foam

报道了二维泡沫形成和进化的实验装置 ,并研究了二维泡沫的拓扑学性质随时间的变化关系。在二维泡沫的进化中 ,存在着两种进化过程 ,一种是初始有序化的气泡进化 ,另一种是完全无序化的气泡进化。在无序化气泡的进化过程中 ,平均气泡面积随时间的变化呈现出幂指数关系 :α =1 5。这个时间指数大于VonNeumann定律的时间指数。此外 ,气泡的边数分布和边数分布的 2级动差亦被讨论An experimental study of the evolution of two-dimensional foam is presented. The topological properties of two-dimentional foam as a function of the evolution time is investigated. In the evolution of two-dimensional foam, two distinct states are observed: a transient characterized by the presence of ordered state and a long-term fully disordered state. The long-term behavior of the foam shows that the average bubble area increases as a power law with exponent α=15, which is deviation from Von Neumann law. In addition, the distribution of sides of bubbles and the second moment of the distribution of number of sides are discussed.国家自然科学基金资助项目!(29973033

Purification of Multiwalled Carbon Nanotubes and Characterization of Their Oxygen-Containing Surface Groups

Corresponding author. Email: [email protected].[中文文摘]用兼具酸性和氧化性的HNO3水溶液可方便地除去残留在原生态多壁碳纳米管(CNT)上的Ni-MgO催化剂组分,同时在其表面产生某些含氧官能团,使原生态多壁碳纳米管的疏水性表面变为亲水性表面.采用Boehm中和滴定法以及X射线衍射(XRD)、热脱附谱(TPD)、傅里叶变换红外(FTIR)光谱和X射线光电子能谱(XPS)等技术对HNO3处理过的多壁碳纳米管的相组成和表面含氧官能团进行测量和表征.结果表明:所生成表面含氧官能团的总量以经7.0mol·L-1硝酸378K处理24h的CNT为最高;3种主要表面含氧官能团的含量高低顺序为,羧基>内酯型羧基>酚型羟基.[英文文摘]We conveniently removed the Ni-MgO catalyst components from an as-grown multiwalled carbon nanotube (CNT) using an aqueous HNO3 solution with strong acidity and oxidizability as a purifying reagent. Some oxygen-containing surface groups were generated at the CNT surface, which converted the hydrophobic surface into a hydrophilic surface. The phase composition and the oxygen-containing surface groups of the CNTs treated by nitric acid were determined and characterized using Boehm′s neutralizing titration method and X-ray powder diffraction (XRD), temperature-programmed desorption (TPD), Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) techniques. The results indicated that the total content of the formed oxygen-containing surface groups was the highest for the CNTs treated with 7.0 mol·L-1 aqueous HNO3 at 378 K for 24 h. The content of the three major oxygen-containing surface groups was: carboxyl>lactonic carboxyl>phenolic hydroxyl.国家重点基础研究发展规划项目(973)(2009CB939804);福建省重大科技专项专题项目(2009HZ0002-1

Effects of Cadmium Stress on Seed Germination and Seedling Growth of Dwarf Beans

为比较系统地探讨Cd2+的生物毒性,作者以水培法研究了不同浓度的Cd2+溶液对四季豆种子萌发和幼苗生长发育过程中植物外部生长指标及内部生理生化变化的影响。结果表明:当Cd2+浓度较低时,Cd2+对种子萌发及幼苗生长发育毒害作用较小,一定浓度范围内(0.05~0.5Mg/l)还有促生作用,高浓度Cd2+(5~100Mg/l)能严重抑制四季豆幼苗根及下胚轴的生长;Cd2+胁迫对四季豆幼苗体内过氧化物酶(POd),超氧化物歧化酶(SOd),过氧化氢酶(CAT)活性存在低浓度激活和高浓度抑制的效应,且同一浓度的Cd2+对四季豆幼苗POd、CAT活性的抑制作用表现为根系大于下胚轴,Cd2+浓度>0.5Mg/l时,根系SOd活性大于下胚轴中的活性;Cd2+胁迫下,四季豆下胚轴和根的丙二醛(MdA)含量增加,且根部含量大于下胚轴的量。Cd2+对矮生四季豆种苗生长发育的影响因Cd2+浓度及幼苗部位的不同而异。In order to explore the biological toxicity of Cd2+more systematically, the effects of Cd2+ on the external and internal physiological and biochemical changes in the process of dwarf beans seed germination and seedling growth were studied with hydroponic culture experiments.The results showed that when the concentration of Cd2+ at low level, the effects of Cd2+ on the seed germination and seedling growth were not significant.Seeds germination were activated at a certain extent when Cd2+ concentration ranged from 0.05mg/L to 0.5 mg/L concentrations.The roots and Hypocotyls of seedling exhibited a significant decrease in growth at higher level of Cd2+ concentrations (5～100mg/L).The activities of peroxidase (POD), superoxide dismutase (SOD), catalase (CAT)could be enhanced at low Cd2+concentrations but inhibited at higher concentration.The activities of POD, CAT were more inhibited in roots than in Hypocotyls at the same Cd2+ concentrations, while that of SOD was higher in roots than in Hypocotyls when the concentration of Cd2+ was more than 0.5mg/L.The malondialdehyde (MDA) contents were continuously increased with Cadmium exposure in both roots and Hypocotyls.The effects of Cd2+on the dwarf beans’growth were varied with the concentration of Cd2+ and the parts of plants.“2007AA10Z441”项目的资助;“07JC14025”项目的资助;“07DZ12055”项目的资

Ecotoxicological Effects of Lead and Copper on Seed Germination of Wheat

通过种子萌发试验,研究了不同浓度的Pb2+和Cu2+对小麦种子萌发、幼苗生长以及对小麦α-淀粉酶活性的生态毒理效应。结果表明:Pb2+在低浓度下(5Mg·l-1)对小麦种子萌发过程中的各项指标皆为抑制作用;Pb2+、Cu2+胁迫对小麦α-淀粉酶活性存在低浓度激活和高浓度抑制的效应,且浓度越高,抑制作用越强;Cu2+对小麦种子萌发各项指标的抑制率大于Pb2+,Pb2+、Cu2+对小麦根生长的毒害作用大于对地上部的影响。By seed germination experiments, We studied ecotoxicological effects of Pb2+, Cu2+ on the seed germination, seedling growth and α-amylase activity of wheat.The results showed that the seed germination and seedling growth of wheat could be promoted at low concentrations of Pb2+ (under 0.5 mg·L-1), while they would be inhibited when the concentration of Pb2+ was high; Cu2+ in high concentrations (above 5 mg·L-1) could reduce the germination rate, the seedling growth and vigor markedly; the activity of α-amylase could be enhanced at low concentrations of Pb2+ or Cu2+ but be inhibited at high concentrations, and the injury became severer with the increase of concentration; the inhibition of Cu2+ on seedling growth indices of wheat were larger than that of Pb2+, the stress effects of Pb2+ or Cu2+ was stronger on seed germination than seedling growth.国家高技术研究发展计划(863计划)项目(2007AA10Z441);上海市科委项目(07DZ12055);上海市科委项目(07JC14025

Analysis on epidemiological charateristics of chlamydia trachomatis infection in Jiangsu Province,2006-2011

目的了解江苏省2006-2011年生殖道沙眼衣原体感染的流行病学特征,为制定防治生殖道沙眼衣原体感染的策略提供科学依据。方法收集2006-2011年江苏省通过中国疾病预防控制信息系统报告的生殖道沙眼衣原体感染病例资料,并对资料进行流行病学分析。结果 2006-2011年,江苏省生殖道沙眼衣原体感染发病率呈快速上升的趋势,2006年为0.12/10万,2011年为3.15/10万,发病率年均增长速度为92.23%;在报告的5 859例病例中,男女性别比为0.3∶1,各年生殖道沙眼衣原体感染男女性别差异有统计学意义;发病年龄主要集中在20~29岁年龄组,占50.96%;江苏省生殖道沙眼衣原体感染报告病例主要集中在苏南和苏中的较发达城市;主要以家庭及待业者和工人为主。结论江苏省生殖道沙眼衣原体感染发病率快速增长,应加强对生殖道沙眼衣原体的防治,以控制其感染的快速流行。江苏省医学重点人才(RC2011086);江苏省医学重点人才(RC2011087); 江苏省科技项目(Y201029